Composite building board and method of making same



C. W. UTZMAN COMPOSITE BUILDING BOARD AND METHOD OF M Filed June 14,1922 CLARENCE W. no H, OH BUBFALQ, NEW YORK, ASSIGNOR, BYIEESNEASSIGNMENTS,

TO '1 BEAVER I 'RODUCTS COEANY, INC., A CORPORATION OF NEW Y:

COMPOSITE BUILDING B0 f AND METHGD OF BEING: SAME.

Applicationfiled June 14, 1922. erial lilo. 568,273.

To all whom it may concern:

Be it known that CLARENCE W. U'rzMAN, a citizen of the United States,and a resident of the city of Bufialo, in the county of Erie,

-' State of New York, has invented an Tmprovement in Composite BuildingBoard and Methods of Making Same, of which the following is aspecification.

This invention relates to composite building board, such as plasterboard or the like,

and tothe method of making it.

Among other objects, the invention is intended to provide an improvedbuilding board, such as plaster board, the edges of 1a which areprotected by the margins of the covering material and which are finisheded in such a manner that the ed es of the covering material are notreadily oosened or torn.

The invention consists in the novel conea structions, combinations andmethods, hereinafter described or claimed, for carrying out the abovestated object and such other objects as will hereinafter appear.

The invention may be more readily understood by reference to oneillustrative method and construction embodying the invention and shownin the accompanying drawing.

In said drawing: Fi 1 is a perspective view of a portion of the p asterboard. Fig. 2 is a cross section thereof taken along the .line 2-2 ofFig. 1.

Fig. 3 is a cross section similar to Fig. 2 but illustrating the boardas it appears at an intermediate stage of manufacture.

This application is a continuation in part of my prlor application Ser.374,833, filed April 19, 1920.

The invention is illustrated as applied to a double-face plaster board,that is, a board either side of which may be employed as the face sideof the board. In the drawing, 10

and 11 designate cover sheets, which may be termed for convenience toand bottom cover sheets, respectively. Suc cover sheets are preferablyof fibrous material of the proper weight and quality, such as paper.Between the cover sheets is a body 120i plaster or the like to which thecover sheets preferably adhere.

Preferably, a cover sheet 10 somewhat wider than the intended width ofthe board is employed to. provide margins 13 which may be folded overthe edge of the board. The edges'l i: of the cover sheet are preferablybeveled or otherwise reduced in thickness to a thin edge so that, whenthe margins are cemented in place, the free edges of the cover sheetmerge into the edge of the board and are practically obliterated. Theydo not therefore present any projectin edges which might become caughtand resu t in loosened or torn paper. r V K In the illustrative board,the cover sheet 11 is also somewhat wider than the intended width of theboard, providing margins 15 which are folded over the edge of theplaster body. In this arrangement the margins 13 are folded over the marins 15 and cemented in place by any suitab%e adhesive, such as plasteror glue, which will resist the action of moisture and heat to which itmay be exposed during the various steps in the manufacture of the board.Tf desired, the margins 13 may be made of such a width as to extendsubstantially across the entire edge of the board. 1

Plaster board of this character may be manufactured in any suitablemanner. If what is termed as the continuous process be employed, plasteris placed in suitable quantities upon a traveling cover sheet, calledthe bottom sheet. As illustrated, the cover sheet 11 may conveniently beemployed as the bottom sheet and the margins 15 thereof turned up atsome stage of the manufacture of the board to confine the plasterbetween the upturned margins. The top cover sheet is applied and theplaster spread to an even depth across'the board.

At some stage in the manufacture of theboard, either before or after theapplication of the top cover sheet to. the plaster, though preferablybefore, the marg1ns 13 thereof are beveled or suitably reduced inthickness at the entreme edges to provide athin edge which when cementedin place will rovide no means by which the margins may ecome caught andtorn or loosened. In the construction illustrated in Fig. 3, the underside of the margins 13 is beveled, This may be conveniently accomplishedby passing the margins over grindin devices, such as rapidly rotatingemery w eels, having grinding surfaces. arranged at the proper an Is toproduce the required bevel. After t is treatment of the margins 13, theyare cemented in place firmly so as practically to obliterate any exposedcoversheet edge. The grinding or beveling of the cover sheet edgesremoves the surface loss or finish and so roughe'ns it as to enable itto be substantially united with or merged into the edges of the board.

' Obviously, the construction, conformation or shape of the edges of theboard may be varied according to particular requirements.

If desired, the cover sheets may be scored to weaken the aper along thelines 16 and 17 to permit t e margins to be folded over sharply and toform sharp or square edges on the finished plaster board.

' Obviously, the invention isnot limited to any particular constructionand the details l of the illustrative board and method of makmargins-soas to provide a thin edge therefor and cementing said margins m place,whereby the edges of said margins substantially merge into the surfaceofthe board.

2. The method of making plaster board.

' of the kind described, which comprises providing covering material forthe opposite faces of a body of laster or the like, folding certaincover s eet margins to envelop ,the edges of the body and cementing thesame in lace, said margins being so treated as to su stantiallyobliterate any exposed cover sheet edge.

3. The method .of making plaster board I of the kind described, whichcomprises pro viding covering material for the opposite faces of a bodyof plaster or the like, proedge, and cementin viding cover sheet marginsfor folding over the edge of said body, and treating said margins so assubstantially to obliterate any exposed cover sheet edge when saidmargins are folded in place.

4. The method of making plaster board of the kind described, whichcomprises providing covering material for the opposite faces of a bodyof plaster or the like, providing cover sheet margins for folding overthe edge of said body, reducing the thickness of said margins so as toprovide a thin said margins in place so that said thine ge substantiallymer es into the surface of the edge of said boar 5. The method of makingplaster board the opposite faces 0 messes which comprises applying coversheets to the -o posite faces of a body of plaster or the l e, foldinthe cover sheet margins over the edge 0 the board and cementing the samein place, certain cover sheet margins having been reduced in thicknessso as to bbliterate any exposed cover sheet edge.

6. The method of making plaster board which comprises applying coversheets to the. like, beveling the edges of certain cover a body ofplaster or sheet margins to produce a. thin edge, folding the coversheet margins over the edge of saldbody in overlapping relation withsaid beveled margins on the outside and cementing the same in lace.

. The metho of making plaster board which comprises applying top andbottom cover sheets to a body of plaster, or the like, of reater widththan the intended width of t e board, grinding the margins of one sheetto produce a thin ed e, folding said cover sheet margins over t e edgeof the board with said thin-edge margins exposed,

and cementing the same in place.

8. The met 0d of makingplaster board which comprises applying top andbottom cover sheets to a body of plaster, or the like, of greater widththan the intended width of the board, grinding the under surface of themargins of said top sheet to produce a beveled edge, folding said sheetmargins over the edges of said bod in overlappingrclation, with said tops eet margins exposed, and cementing said margins in place.

9. A laster board comprising, in combination, a body, cover sheetscovering the opposite, faces of said body and adhering thereto toreinforce said body from edge to edge, certain of said cover sheetmargins being folded over the edges of said board and being beveled tomake a thin edge which substantially mel lges into the plane of the edgeof said boa 10. A plaster board comprising, in combination, asubstantially rigid body, cover sheets covering the opposite faces ofsaid body and adhering thereto to reinforce said body from edge to edge,certain of said cover sheet margins being folded over edges of the/bodyand reduced in thickness and cemented in place so as to obliteratesubstantially any exposed edge of said folded marwhich substantiallymerge into the plane of the edge of said board.

said margins being reduced in thickness toprovide thin edges thereformemes 12. A plaster board comprisin' in comhistentielly to obliteratethe line of demarcanation, a plaster body; fibrous s eets cover-' tionbetween it and the underneath margiing opposite feces of the body andadherent ml portion. thereto; the marginal portions of the sheets Intestimony whereof, I have signed my 6 being folded one over the otherand united name to this specification. at the body edge; the outermarginal portion being tapered adjacent its edge suh- CLARENGE W.UTZMAN.

